If desired, you may easily setup your own repository where you can host your own private packages, copy existing public packages over to develop them on your own, or anything else you may need. To create a repository, first ensure the Development Toolkit package is installed on your server. Within terminal change to the installation directory, and type:
php apex.php install devkit
Once installed, visit the Devel Kit->Repositories menu of the administration panel, and you will see one repository listed. Manage that repository, and change the settings as desired such as the name of the repository, whether it's publicly viewable, etc. Through this Repositories menu you may setup multiple repositories on the same system. This is done for organizational purposes, and you simply need to have multiple hostnames pointing to the system, and can setup one repository on each hostname.
If you have access to other repositories, you may easily configure them on any individual system. In terminal, type:
php apex.php add_repo HOSTNAME USER PASS
Obviously, change the hostname, username and password above as needed. Once added, upon searching for or installing packages, the system will also begin contacting the new repository as well. The same applies if using your own repository to publish and manage packages that you wish to distribute to clients. Simply give clients the hostname to your repository, they can add it as above, then install any packages available on your repository with the standard command:
apex.php install PACKAGE